选矿产品矿物自动分析的光片制备

基于扫描电子显微镜的矿物自动分析仪(Quantitative Evaluation of Minerals by Scanning Electronic Microscopy)、MLA(Mineral Liberation Analyser)和AMICS(Advanced Mineral Identification and Characterization System)可用于测定选矿产品中目的矿物的粒度和单体解离度,为确定合理的磨矿细度以及优化选矿工艺流程提供依据。环氧树脂光片的制备是矿物自动识别和测量的最关键的一环,其代表性直接关系到后续数据测量的准确性和真实性。对于金属矿产品来说,由于选矿产品中矿物颗粒粗细不均、密度差异较大,在环氧树脂胶结固化过程中矿物颗粒会产生明显的分异作用并互相黏连,造成分析结果失真。实验证明,把样品与晶质石墨混均,然后加入环氧树脂以及固化剂搅拌混合倒入圆柱状模具进行冷镶嵌,待样品固化后再沿圆柱体的纵向进行切割,并对其切割面进行粗磨、细磨、精磨以及抛光,就可以制备出样品分散性好、分布均匀、表面光滑平整的具有代表性的环氧树脂光片。

Polished section sample preparation of mineral processing products for mineral automatic analysis

Mineral automatic analysis basing on scanning electron microscope, such as QEMSCAN (Quantitative Evaluation of Minerals by Scanning Electronic Microscopy), MLA(Mineral Liberation Analyser), and AMICS(Advanced Mineral Identification and Characterization System)can be used to study and measure grain size and liberation degree of target minerals in mineral processing products. Through these data, a reasonable suggestion for grind-fineness and mineral processing flowsheet can be provided. To achieve these aims, the step of sample polished section preparation is important, the representativeness of which is directly influence the veracity and authenticity of measurement results. For metallic ore, the mineral processing products are characteristic by variation of mineral grain size, density variation of different type minerals. In this situation, a differentiation process and conglutination may happen easily during the curing process of epoxy resin, which result a distortion of measurement data in following steps. This paper provide a sample preparation method to assure sample representativeness: a mixture of sample and crystal graphite was added into a mixing liquid which include epoxy resin and curing agent, and then stir and pour into a cylinder mode. After solidification, a longitudinal cutting did to expose the longitudinal section. Then a process including a series of grinding steps and polishing were done focusing on this section. Through this method, it is possible to produce a representative polish section with smooth surface, samples in which are also with good dispersibility and balance distribution.